VATICAN CITY (CNS) -- The controversy over a traditionalist bishop who has minimized the full extent of the Holocaust was fueled in part by a lack of communication within the Vatican, said a cardinal who coordinates Vatican dialogue with the Jews.

"Up to now people in the Vatican have spoken too little with each other and have not checked where problems might arise," Cardinal Walter Kasper told Vatican Radio's German program Feb. 2.

"There were misunderstandings and management errors in the Curia," he said, in reference to the lifting of the excommunication of British-born Bishop Richard Williamson, who has claimed that reports about the Holocaust were exaggerated and that no Jews died in Nazi gas chambers.

Bishop Williamson was one of four bishops of the traditionalist Society of St. Pius X whose excommunication was lifted by Pope Benedict XVI Jan. 21 -- the same day a Swedish television station aired a November interview with Bishop Williamson in which he repeated his position on the Holocaust.

The papal decree was made public Jan. 24 and Jewish groups expressed shock that the Vatican would lift the excommunication against Bishop Williamson even after his comments had been televised.

Cardinal Kasper said he has been following the unfolding controversy "with great concern."

He said the pope "wanted to open the discussion because he wanted unity inside and outside" the church. But the cardinal said he "would have also liked to see more communication in advance."

"Explaining something after the fact is always much more difficult than if one did it right away," he said.